U.S. Pa. No. 4,314,295 issued to Frandsen and entitled "Linear Actuator With Staggered Flat Coils" discloses a disk drive apparatus which includes an array of flat-coil actuators using a plurality of overlapped flat coil sets interacting with a plurality of surrounding magnets for stepping such actuators into position. In operation, only one of the overlapped coil sets is energized at any one time.
U.S. Pat. No. 4,396,966 issued to Scranton et al and entitled "Low Mass Actuator System For Magnetic Recording Disks With Half Strength End Poles" discloses a linear actuator comprised of a stator including a number of permanent magnets of opposite polarity arranged in an array side by side, and a shuttling armature comprised of a pair of flat coils. At each end of the array of magnets there is provided a half strength magnet for closing the magnetic circuit so as to reduce flux which emanates towards the disk and recording heads of the disk recording system.